A new type of Single-Phase stand-alone induction generator using a three-Phase induction machine and a Single-Phase voltage-source PWM inverter is introduced. The generator scheme is capable of producing constant load frequency with a very well regulated output voltage. A small lead acid battery and a Single-Phase full diode-bridge rectifier are used to feed the inverter. The inverter feeds one of the stator Phases. During the generator voltage build up, the inverter supplies the battery first and after a while a diode-bridge rectifier, which is fed by the generator, replaces if. The system steady state and dynamic equations are derived and are solved to obtain the performance characteristics of the generator scheme. A digital simulation study is carried out for a 2.2 KW three Phase induction machine. The simulated results obtained confirm that this generator can achieve an output power of about 0.6 pu..

In this paper, a new Single-Phase Single-stage high step-up boost inverter appropriate for photovoltaic systems is proposed. In the proposed inverter, the duty cycle of one of the switches is adjusted to control the output voltage and increase the gain. In this structure, the dynamic model is adopted as an appropriate model to describe the low-frequency behavior of converters and extract the equations. Moreover, in this topology, a common ground is used between the input and output which can remove leakage current in different applications, including grid-connected applications. The proposed inverter is simulated using MATLAB/SIMULINK, and the experimental results are presented to verify the theoretical analysis.

This paper presents a Single-Phase topology for multilevel inverters with minimum number of switching devices. The proposed topology significantly reduces the number of DC voltage sources, switches, and power diodes as the number of output voltage levels increases. The proposed multilevel inverter is constructed using series-connection of multilevel strings. Suggested multilevel string is composed of multiple basic switching units. The proposed multilevel inverter has extendable configuration that increases the number of output voltage levels more and more by adding more stages. The proposed multilevel inverter would be implemented in both symmetric and asymmetric configurations. Two different algorithms are introduced for determination of magnitude of DC voltage sources to reach the maximum number of output voltage levels with minimum number of semiconductor devices. Important characteristics of both symmetric and asymmetric configurations are extracted and compared with similar multilevel inverter topologies. Finally, a prototype of the proposed multilevel inverter is simulated and implemented experimentally to verify operation of the proposed multilevel inverter.

In this paper, a metamaterial based toroidal ferrite Phase shifter design algorithm has been introduced in X band. For the design of such a Phase shifter, first the MNG (negative μ ) ferrite core in extraordinary bias mode should be implemented. Then, the ENG (negative ε ) part composed of parallel metallized lines should be designed on a substrate board. Finally, the input and output port impedance matching could be accomplished by using two section dielectric step transformers layout using binomial tapering method. According to the simulation results, the closed toroidal ferrite core shape, has treated the main disadvantage of metamaterial waveguide Phase shifter’ s experimental bias complications, and it has reduced the amplitude of magnetic bias filed from the typical range of (6-7 kOe) to under the acceptable 100 Oe value, which could be achieved using a simple wire. Moreover, by introducing a new core structure and an impedance matching network in the proposed Phase shifter, the second main disadvantage of the metamaterial-based ferrite Phase shifter which is their high insertion loss, has decreased from 10 dB to 3. 2 dB.